I have a whirlpool dryer which has stopped spinning, the motor still runs, and it still heats up. I would like to try and figure out what is wrong with it. The model number is #LER7646DQ0.

If it is like my ancient one, the motor is near the back right corner. Remove the front panel. There is a spring loaded idler between the motor and belt. Carefully note how they work. You may need a new belt. Try http://www.repairclinic.com/0070.asp

This dryer has a removable lower panel on the front. It hinges down from the top. Sometimes the clips that hold it are on the side edges or on the top. If you can get it released (sometimes a putty knife is helpful to release the clips), you will probably see either the belt is broken or just came off the idler. If the belt is broken, you'll need a new one, part number 341241 (most common belt they ever used). If the idler pulley doesn't turn freely, replace it also, part number 691366. While the belt is off, make sure the drum turns freely. If you need help reassembling anything, let me know, as the belt/idler setup confuses easily.